1. Field
Embodiments relate generally to digital communications.
2. Background
Digital communications systems have become pervasive in recent years. Users increasing rely on email, instant messaging, Voice over Internet Protocol (VOIP), video conferencing and other similar types of network based communication channels for exchanging information, including private and confidential information. In general, information transmitted over, for example, the Internet can be intercepted or tapped at various points, such as ISP routers and WIFI access points. As a result, end-to-end encryption is important for protecting confidentiality of digital communication. To use encryption, the communicating parties need to share a secret encryption key first. This is a challenging task because the communicating parties generally do not have secure communication channels among them.
In theory, the public key infrastructure (PKI) provides a solution for this: the communicating parties can publish their public keys, and one party can create a new encryption key and send the key to other parties securely by encrypting the key with public keys of other parties. However, in practice, the usability of PKI is low for individual users because it is difficult for them to manage their private key properly. For example, a user may need to put his private key on every device he might want to use for secure communication, and that makes the key more likely to be leaked. In addition, the damage of a leaked private key is very severe, which means the confidentiality of all the previous private communications derived from the private key may be compromised.